1. Field of the Invention
This invention relates to materials handling systems such as order processing systems and, more particularly, to stations for receiving and sorting picked items for orders.
2. Description of the Related Art
Retailers, wholesalers, and other distributors of product (which may collectively be referred to as distributors) typically maintain an inventory of various items that may be ordered by clients or customers. This inventory may be maintained and processed at a materials handling facility which may include one or more of, but not limited to: warehouses, distribution centers, cross-docking facilities, order fulfillment facilities, packaging facilities, shipping facilities, or other facilities or combinations of facilities for performing one or more functions of material (inventory) handling. FIG. 1 illustrates a broad view of the operation of a conventional materials handling facility. Multiple customers 10 may submit orders 20 to the distributor, where each order 20 specifies one or more items from inventory 30 to be shipped to the customer that submitted the order. To fulfill the customer orders 20, the one or more items specified in each order may be retrieved or “picked” from inventory 30 (which may also be referred to as stock storage) in the materials handling facility, as indicated at 40. Picked items may be delivered to one or more stations in the materials handling facility for sorting 50 into their respective orders, packing 60, and finally shipping 70 to the customers 10. Note that a picked, packed and shipped order does not necessarily include all of the items ordered by the customer; a shipped order may include only a subset of the ordered items available to ship at one time from one inventory-storing location. Also note that a materials handling facility typically also includes a receiving operation for receiving shipments of stock from various vendors and placing the received stock into stock storage. Further, note that the various operations of a materials handling facility may be located in one building or facility, or alternatively may be spread or subdivided across two or more buildings or facilities.
FIG. 2 illustrates an exemplary physical layout of a conventional material handling facility, specifically an order fulfillment facility, or center. At any time, one or more agents of the distributor may each be picking items from inventory 30 to fulfill portions or all of one or more orders. This may result in a stream and/or batches of picked items for multiple incomplete or complete orders being delivered to a sorting station 50 for sorting into their respective orders for packing 60 and shipping 70. A stream may be a continuous or nearly continuous flow of picked items arriving at a sorting station 50, while groups of picked items arriving periodically or aperiodically at a sorting station 50 may be referred to as batches. Note that portions of an order may be received at different times, so sorting 50 and packing 60 may have to wait for one or more items for some orders to be delivered to the sorting station(s) 50 before completion of processing of the orders. The stream or batches of incoming picked items are sorted into their respective orders at the sorting station(s) 50. Conventionally, the picked items may be sorted into a fixed array of “pigeon holes” or slots, with each slot receiving one order. Once an order is completed at a sorting station 50, the order is ready to proceed to a packing station 60 to be packaged for shipping 70. Note that an order fulfillment center may also include one or more receiving stations for receiving shipments of stock from various vendors. The received stock may then be placed into stock storage. Further, note that the various operations and stations of an order fulfillment center may be located in one building or facility, or alternatively may be spread or subdivided across two or more buildings or facilities.
A materials handling facility such as an order fulfillment center 80 may implement an order fulfillment control system, or control system for short. A control system (not shown) may include hardware and software configured for assisting and/or directing agents in the order fulfillment center 80 in fulfilling customers' orders. Items in inventory 30 may be marked or tagged with a bar code, radio frequency identification (RFID) tag, Universal Product Code (UPC), Stock-Keeping Unit (SKU) code, serial number, and/or other designation (including proprietary designations) to facilitate order fulfillment center 80 operations, including, but not limited to, picking, sorting 50 and packing 60. These designations, or codes, may identify items by type, and/or may identify individual items within a type of item. The control system may include hand-held, mobile and/or fixed scanners or scanning devices that may be able to scan the marks or tags on individual items to determine and record the item and/or item type of the items.
The control system may be able to receive order information for each order specifying the item or items to be picked to fulfill the order. Each order may be assigned a unique order number for use in the order fulfillment process. Item and/or item type information, including associated item and/or item type designations or codes and possibly other descriptive information, may be entered into the control system for each item picked to fulfill each order. This information may be scanned into the control system from marks or tags on the items or, alternatively, manually entered. A combination of scanning and manual entry may be employed during picking.
Conventionally, sorting 50 may be performed using automated sorting mechanisms or manual sorting systems. Automated sorting mechanisms for sorting certain types of inventory items according to individual orders include, but are not limited to, the Crisplant® sorter, Eurosort® sorters, and automated sorting mechanisms offered by other vendors. Using an automated sorting mechanism, batches or a stream of incoming picked items for multiple different customer orders are received at the automated sorting mechanism and sorted by the automated mechanism according to individual orders. Such automated sorting mechanisms are typically expensive in both cost and floor area. Further, automated sorting mechanisms tend to be more expensive than manual sorting systems in situations where inventory throughput demands may vary significantly, for example from month to month, and/or where inventory throughput demands may increase rapidly over time, due to the need to pay for fixed automation equipment that may only be fully utilized at peak demand periods.